Cover accessory device for a portable electronic and/or computer apparatus, and apparatus provided with such an accessory device

ABSTRACT

The present invention relates to a device for a portable user apparatus, including a portion which can be folded over the user apparatus, said foldable portion including at least two detection layers, each kept at a guard potential and including at least one capacitive detection electrode: a first of said layers being arranged to carry out a function of capacitive detection of at least one control object located on one side of said foldable portion; a second of said layers being arranged so as to carry out a function of capacitive detection of at least one control object located on the other side of said foldable portion, with a view to triggering a function in the user apparatus. The invention also relates to an apparatus provided with such an accessory device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Phase application under 35 U.S.C. § 371of International Application No. PCT/EP2014/074351, filed Nov. 12, 2014,which claims the priority benefit of French Patent Application No.1361330, filed Nov. 19, 2013, the contents of which are herebyincorporated by reference in their entireties for all intended purposes.

TECHNICAL DOMAIN

The present invention relates to a covering accessory device for aportable electronic and/or computer apparatus, providing a function ofdetection of a command object. It also relates to a portable electronicand/or computer apparatus equipped with such an accessory device.

The domain of the invention is more specifically, but withoutlimitation, that of contactless human-machine interfaces, implementing acapacitive detection technology, and still more specifically acapacitive detection technology implementing a guard plane forcapacitive electrodes.

STATE OF THE ART

There are currently on the market many accessories aiming to coverportable electronic and/or computer apparatus, such as portablemicrocomputers, digital tablets or smart phones. These accessoriesgenerally have a function of protection against impacts and scratchesand also aesthetic and personalization function. These accessories cancome in various forms: sleeves, pockets, covers, flexible or rigidenvelopes and shells.

Some of these accessories have a foldable flap intended to cover thescreen and possibly the keyboard of portable apparatus. This flapprotects the front surface of the portable apparatus when it is foldedthereunto and opening it releases the screen and command functions.

Furthermore, more and more portable apparatus, such as tablets and smartphones are equipped with a touchscreen and provide Human-MachineInterface (HMI) functions. These apparatus use, as an interface,touchpads which are transparent on the screens and opaque in the area ofa command surface arranged on the periphery of the screen. Most of thesepads use capacitive technology. With this technology, one or morecommand objects (fingers, stylus, etc.) can be detected in contact withor at a distance from the command surface; this technology implementsthe capacitive technology described in the patents FR 2,893,711 or FR2,949,007, or again in the patent application FR 2,971,666 A1, filed bythe Applicant.

However, the detection functionality is currently limited to theelectronic/computer apparatus. When this apparatus is provided with anaccessory device comprising a movable part, such as for example afoldable protective cover, it is first necessary to handle theprotective cover to leave access to the command surface and then tostart to interact with the apparatus.

Additionally accessory devices, of protective cover with foldable flaptype, are currently used to satisfy a single function which is apparatusprotection.

An object of the present invention is to remedy the aforementioneddisadvantages.

Another object of the present invention is to propose a protectiveaccessory device for a computer/electronic apparatus providing morefunctionalities than currently known accessory devices.

Again another object of the present invention is to propose a protectiveaccessory device for a computer/electronic apparatus contributing to, oreven improving, the detection functionalities of such an apparatus.

Finally, it is an object of the present invention to propose aprotective accessory device for a computer/electronic apparatus allowinga faster interaction and requiring less handling of said apparatus.

DESCRIPTION OF THE INVENTION

The invention proposes to achieve at least one of the aforementionedobjects with a device for a portable electronic and/or computerapparatus, called user apparatus, where said device comprises a partwhich folds in order to cover at least one part of said user apparatuswhen it is folded onto said user apparatus, characterized in that saidfoldable part comprises at least 2 detection layers, each guarded at oneguard potential and comprising at least one, preferably several,capacitive detection electrode(s):

-   -   a first of said layers being arranged to perform a capacitive        detection function of at least one command object located on one        side of said foldable part, in particular the side of the inner        surface of said foldable part located on the side of said user        apparatus when it is folded onto said user apparatus;    -   a second of said layers being arranged to perform a capacitive        detection function of at least one command object located on the        other side of said foldable part, in particular the side of the        outer surface of said foldable part when it is folded onto said        user apparatus;        in order to trigger a function in said user apparatus.

In that way, one has a device, and more precisely an accessory device,with which to perform a capacitive detection function for a portableapparatus while also performing a removable protective cover function.In that way, a compact and operational equipment results whatever theeffective position of the foldable part. Consequently, the deviceaccording to the invention provides more functionalities than theaccessory devices from the state-of-the-art which only provide aprotective function for the user apparatus.

Additionally, with the device according to the invention, it is possibleto detect a command object even when the foldable part of the device isfolded onto the apparatus and to trigger a function done by the userapparatus. In that way, it is possible to interact with the userapparatus without having to handle the foldable part of the device,allowing a faster interaction with less handling for the user.

The device according to the invention serves to perform a detection of acommand object by a layer of guarded capacitive electrodes, which allowsan improved detection of the command object.

Furthermore, the device according to the invention serves to perform adetection of a command object whatever the position of the foldablepart, in that way offering the user more freedom in the positioning ofthe foldable part and consequently in the control of their apparatus. Infact, with the device according to the invention, the user can trigger afunction in the user apparatus, whatever the position of the movablepart.

Preferably, the detection layers are not coplanar, each of the detectionlayers forming a plane substantially parallel to the plane defined bythe foldable part and/or the plane defined by at least one otherdetection layer.

The electrodes from at least one, preferably each, detection layer canperform an autonomous detection, in “self-detection” mode or a detectionby cooperating with another electrode, in “mutual-detection” mode.

In a preferred, but in no way limiting, version one of the capacitiveelectrode layers is parallel to the surface of the user apparatusserving to form a display and/or comprising a touchpad provided withcapacitive electrodes when the movable part is folded onto the userapparatus.

In a preferred, but in no way limiting, version the first capacitiveelectrode layer is also called “inner layer” and is arranged on the sideof a surface, called inner, of the foldable part coming into contactwith the user apparatus when the foldable part is folded onto the userapparatus, and the second layer of capacitive electrodes is also called“outer layer” and is arranged on the side of a surface called outeropposite said inner surface.

In a particular embodiment, for at least one position and/or at leastone given moment, both detection layers can be activated in detection.In this case, for at least one given moment or at least one givenposition of the foldable part, the device according to the inventionperforms a detection near both surfaces of the foldable part.

According to an advantageous embodiment, each of said first and secondlayers can be activated in detection in turn, depending upon therelative position of the foldable part with respect to the userapparatus such that for a given position of said foldable part just oneof said layers performs the detection function.

For example, when the foldable part is completely folded back onto theapparatus, only the outer layer may be activated in detection and whenthe foldable part is completely open only the inner layer may beactivated in detection. More generally, when the foldable part has anangle β less than or equal to a preset first threshold value, only theouter layer can be activated in detection, and when the foldable parthas an angle β greater than or equal to a preset second threshold value,only the inner layer can be activated in detection.

Of course, the first and second threshold values can be identical ordifferent. The threshold value or values can be included between 45° and135°, and in particular equal to 90°.

Alternatively, the activation in detection (respectively deactivationfrom detection) of at least one, preferably of each, detection layer canbe done either by the user or by the user apparatus or even by ahuman-machine interface, or more generally an application running on theuser apparatus. In this case, activation in detection (respectivelydeactivation from detection) is done, not as a function of the anglebetween the foldable part and the user apparatus, but by the user or byan application running on the user apparatus.

According to a first implementation version, the device according to theinvention can further comprise at least one guard plane arranged betweenthe first and second detection layers and placed at guard potential inorder to guard at least one of said first and second detection layersduring the detection of at least one command object.

In this case, the one or each guard plane is arranged between thedetection layers.

The device according to the invention may comprise a dedicated guardplane for each detection layer.

According to an advantageous alternative of this first implementationversion, the device according to the invention may comprise a singleguard plane arranged between the first and second detection layers inorder to guard each of said detection layers. Thus, with a single guardplane, the device according to the invention serves to guard twodifferent detection layers.

According to a second particularly advantageous and preferredimplementation version, the device according to the invention does notinclude a guard plane in addition to the detection layers. In thissecond version, each of the first and second detection layers performsin turn the role of:

-   -   either the detection function;    -   or a guard function for the other of said capacitive detection        layers by being placed at an alternating potential (V_(G)),        called guard;        the function performed by each of said layers depending on the        relative position of said foldable part relative to said user        apparatus.

In that way, when one of the detection layers is used in detection, theother of the detection layers is used as guard plane, and vice versa. Inthis version, the device according to the invention serves to avoid theuse of a guard plane in addition to the detection planes. In that way,the device according to the invention has a more compact architectureand is less complex and less costly to implement.

In that way, the device according to the invention automatically adaptsand changes the respective functions of the electrode layers equippingthe foldable part, and in particular the inner surface and outer surfaceof the foldable part.

For example, when the movable part is folded back: the inner layer canbe set up to implement the guard function and the outer layer can be setup to implement the detection function and when the movable part is openand reaches an angle greater than a set angle relative to a surface ofthe apparatus: the inner layer can be set up to provide the detectionfunction and the outer layer can be set up to provide the guardfunction.

In other words, and more generally, the inner layer and the outer layercan be set up such that the function done by each layer is chosendepending on the angle β between the movable part and the userapparatus, such that:

-   -   when β is less than a first set value, the inner layer provides        a guard function and the outer layer provides a detection        function, and    -   when β is greater than a second set value, the inner layer        provides a detection function and the outer layer provides a        guard function.

Of course, the first and second threshold values can be identical ordifferent. The threshold value or values can be included between 45° and135°, and in particular equal to 90°.

Alternatively, the activation (respectively the deactivation) indetection or in guard of at least one, preferably of each, detectionlayer can be done either by the user or by the user apparatus or even bya human-machine interface, or more generally an application running onthe user apparatus. In this case, the functions (detection or guard) ofeach layer are decided not according to the angle of the folded partrelative to the user apparatus, but by the user or by an applicationrunning on the user apparatus.

Advantageously, the respective electrodes of each layer can be arrangedso as to substantially mask each other. It can advantageously be thesame for the respective connecting tracks of each detection layer whichhave to substantially mask each other.

The device according to the invention can further advantageouslycomprise at least one means of control in order to determine, dependingon the position of the foldable part, which of the electrode layers ofthe foldable part must implement the detection function and in order toactivate the electrodes from said detection layer in measurement mode.

When the other detection layer is used as guard for guarding the layeractivated in detection, the means of control can further be arranged inorder to control placing the electrodes from the other electrode layerat guard potential so as to have the latter perform the guard function.

Advantageously, the control means can be coupled to, or include, a meansof detection/measurement of the position of the foldable part, such asfor example a means for measurement of the angle between the foldablepart and the user apparatus.

The means of detection can be performed by, or include at least, oneelectrode, located on the inner surface of the foldable part and inparticular at least one of the electrodes from the inner detectionlayer, targeting the user apparatus and arranged in order to measure thedistance between the user apparatus and said foldable part. In that way,according to the distance measured by such an electrode, it is possibleto determine the position of the foldable part.

Alternatively, if the mobile apparatus is equipped with a layer ofdetection electrodes, for example arranged in/on a display screen, it isalso possible to use at least one electrode from the detection layer ofsaid apparatus in order to determine the position of the foldable part.To do this, it is sufficient to activate the electrodes measuring thedistance between the foldable part and the user apparatus and deactivatethe targeted electrodes, at least during the measurement time, or to usedifferent excitation frequencies on the different layers so that theelectrodes from several detection layers do not disrupt each other.

Advantageously, at least one layer of electrodes is arranged in order toperform a detection of at least one command object with or withoutcontact. In this way, the device according to the invention performs acapacitive command detection function which can be “multitouch” and/or“touchless” type.

The device according to the invention can be removable and include, atleast one means of connection to the user apparatus.

This means of connection can be arranged to implement a wired orwireless connection with the user apparatus.

According to an implementation example which is in no way limiting, themeans of connection can, for example, be incorporated in a portion ofshell of the device according to the invention, connected to thefoldable part and arranged in order to be substituted for or arranged ona rear shell of the user apparatus.

The device according to the invention can alternatively be non-removableand be an integral part of the user apparatus.

In a preferred implementation example, the foldable part of the deviceaccording to the invention may comprise a transparent area allowingvisual access to a zone of the user apparatus such as a display screenor a portion of a display screen. In that way, it is possible to view adisplay screen from the user apparatus while interacting with the userapparatus by means of the device according to the invention, withouthaving to open the foldable part.

When the device according to the invention is implemented for a userapparatus comprising a display screen, the foldable part, and inparticular the transparent area of the foldable part, can be configuredin order to be positioned on or against said screen when it is folded.

In this case at least one, preferably each, detection layer can include,at said transparent area level, electrodes made of a transparentmaterial, for example in “Indium Tin Oxide” ITO technology, in order toconserve visual transparency around the transparent zone.

Alternatively, the transparent zone might not be provided withelectrodes.

The foldable part may alternatively or additionally comprise an opaquearea. In this case, at least one, preferably each, of the detectionlayers can include, at said opaque area level, electrodes made with PCB,Printed Circuit Board, technology.

In a specific configuration of an accessory according to the invention,the foldable part acting as a cover is arranged in order to provide indeployed capacitive detection area substantially in the extension of thescreen of the user apparatus. This configuration in particular providesthe user a possibility of control without Joystick type contact soughtby some game consoles.

Advantageously the foldable part has a thickness greater than or equalto 0.5 mm.

According to another aspect of the invention, a portable electronicand/or computer apparatus comprising an accessory device according tothe invention is proposed.

This portable apparatus according to the invention can be provided witha rear shell which is advantageously substituted by a rear shell part ofan accessory device according to the invention.

The portable apparatus can comprise a display screen and the foldablepart of the device according to the invention can be positioned so as tofold at least in part over said display screen.

The apparatus according to the invention may be a computer, telephone orsmart phone, a game console, a PDA, a touch tablet, etc.

DESCRIPTION OF THE FIGURES AND EMBODIMENTS

Other advantages and features will appear from an examination of thedetailed description of examples which are in no way limiting and of theattached drawings on which:

FIGS. 1-3 are schematic representations of the device according to theinvention in three different configurations.

FIGS. 4-6 are schematic representations, in section view, of threeimplementation examples of a foldable part of a device according to theinvention.

FIG. 7 is a schematic representation of a control module for a deviceaccording to the invention.

FIG. 8 is a schematic representation of the operation of the foldablepart shown in FIG. 6; and

FIGS. 9-11 are schematic representations of an apparatus according tothe invention, in which a portion of the device according to theinvention is substituted for a rear shell of said user apparatus.

It is well understood that the embodiments which will be described inthe following are in no way limiting. One could in particular imaginevariants of the invention only comprising a selection of featuressubsequently described isolated from other features described, if thisselection of features is sufficient to confer a technical advantage orfor distinguishing the invention from the state of the prior art. Thisselection includes at least one preferably functional feature withoutstructural details, or with only a portion of the structural details, ifthis part alone is sufficient to give a technical advantage or todistinguish the invention compared to the state of the prior art.

In particular, all the variants and all the embodiments described can becombined with each other if at the technical level nothing prevents it.

In the figures, the elements common to several figures retain the samereference.

We are now going to describe different examples of anelectronic/computer device according to the invention implementingdifferent embodiments of an accessory device according to the invention.

FIGS. 1 to 3 are schematic representations of a nonlimiting example of adevice 100 according to the invention for user apparatus 102 such as asmart Phone® or a digital tablet.

The device 100 comes in the form of a protective cover for the userapparatus 102 and comprises a part 104 foldable relative to the userapparatus and a part 106 fixed relative to the user apparatus.

The fixed part 106 functions as a shell for the rear of the userapparatus 102 and envelops the user apparatus 102.

The foldable part 104 is mechanically connected to the fixed part 106 bya flexible connection 108 and can be rotated around this flexibleconnection 108 in order to be opened or be folded against the userapparatus 102. The foldable part 104 is intended to cover the screen 110of the apparatus 102 in folded position. In FIG. 1, the foldable part104 is open so as to form an angle β substantially equal to 135° withthe plane formed by the screen 110 of the user apparatus 102. In FIG. 2,the foldable part 104 is open so as to form an angle β substantiallyequal to 180° with the plane formed by the screen 110 of the userapparatus 102. In FIG. 3, the foldable part 104 is closed or in foldedposition so as to form an angle β substantially equal to 0° with theplane formed by the screen 110 of the user apparatus 102.

FIGS. 4-6 are schematic representations, according to a section view, ofthree implementation examples of a foldable part 104.

Whatever the embodiment, the foldable part 104 comprises:

-   -   a carrying structure 402;    -   an inner surface 404 provided for coming into contact with the        user apparatus 102, and more specifically the screen 110 of the        user apparatus, when the foldable part 104 is completely folded,        such as shown in FIG. 3; and    -   an outer surface 406 opposite the inner surface 404.

The inner surface 404 comprises a detection layer 408, called inner,formed by a set of capacitive detection electrodes (not shown) and theouter surface 406 comprises a detection layer 410, called outer, formedby a set of capacitive detection electrodes (not shown). Each detectionlayer 408 and 410 is provided and laid out in order to implementdetection, with or without contact, of one or more command objects suchas a finger, hand or stylus. Connecting tracks (not shown) areassociated with each of the detection layers 408 and 410.

When the foldable part comprises a transparent area made of transparentmaterial, the electrodes for each of the detection layers 408 and 410and the connecting tracks which are found at the transparent area levelare made using ITO (“Indium Tin Oxide”) technology. When the foldablepart 102 is completely opaque, the detection electrodes and connectingtracks are made with PCB (“Printed Circuit Board”) type technologies,flexible or rigid, surrounded or not with a dielectric for protection.

In the example shown in FIG. 4, the foldable part 104 ₁ furthercomprises a guard plane 412, called inner, associated with the innerdetection layer 408 and provided for guarding the electrodes of saidinner layer 408 when this layer is used for detecting one or morecommand objects. The foldable part 104 ₁ also comprises a guard plane414, called outer, associated with the outer detection layer 410 andprovided for guarding the electrodes of said outer layer 410 when thelatter is used for detecting one or more command objects. Each guardplane 412 and 414 is placed at an alternating potential V_(G), of agiven frequency.

In the example shown in FIG. 5, the foldable part 104 ₂ comprises asingle guard plane 502 shared by the inner 408 and outer 410 detectionlayers. This single guard plane 502 is placed at an alternating guardpotential V_(G), of a given frequency and serves to guard each of thedetection layers 408 and 410.

In the example shown in FIG. 6, the foldable part 104 ₃ comprises onlythe inner detection layers 408 and 410 and does not comprise a guardplane in addition to the detection layers 408 and 410. In thisembodiment, when one of the detection layers 408 and 410 is used indetection, the other one of the detection layers 410 and 408 is used inorder to form a guard by being placed at a guard potential and in thatway guarding the detection layer activated in detection.

FIG. 7 is a schematic representation in diagram form of an examplecontrol and command module of a device according to the invention,controlling the components of the foldable part.

The module 700 shown in FIG. 7 comprises one control unit 702 incommunication with the user apparatus 102 because of a wired or wirelessmeans of communication 704.

The module 700 comprises or is associated with one or more sensors 706,such as one or more optical, capacitive, mechanical or magnetic sensorsmeasuring an angle, a distance or a movement serving to determine therelative position of the foldable part 102 compared to the userapparatus 102.

The control unit is configured to receive signals from a part of theuser apparatus 104 and sensors 706, process the received signals andcontrol the detection layers 408 and 410 and possibly the guard planes412, 414 and 502.

Additionally, the control unit 702 is also configured for receivingsignals from each of the detection layers 408 and 410 and informing theuser apparatus 102 of the one or more positions of the one or morecommand objects detected by each of the detection layers 408 and 410.

We are now going to describe the operation of the control unit 702, whenthe device comprises the foldable part 104 ₁ shown in FIG. 4.

In a first variant, the control unit 702 can activate the inner 408 andouter 410 layers in detection at any time: in this case, the layers 408and 410 perform a detection function for one or more command objectswhatever the relative position of the foldable part 1041 compared to theuser apparatus 102. In this first variant the guard planes 412 and 414are also activated at any moment and perform the guard function.

In a second variant, the activation of the detection layers 408 and 410is done as a function of the relative position of the foldable part 104₁ relative to the user apparatus. In this variant, depending on therelative position of the foldable part 104 ₁ relative to the userapparatus, each of the detection layers 408 and 410 is activated or not.More generally:

-   -   when the foldable part 104 ₁ has an angle β less than or equal        to a first set threshold value β₁, the control unit 700        deactivates the inner layer 408 and only the outer layer 410 is        activated in detection; and    -   when the foldable part 104 ₁ has an angle β greater than or        equal to a second set threshold value β₂, the outer layer 410 is        deactivated and only the inner layer is activated in detection.

The guard planes 412 and 414 associated respectively with the innerlayer 408 and the outer layer can be activated and deactivated at thesame time as the layer with which they are associated.

Of course, the first threshold value β₁ can be identical, greater thanor less than the second threshold value β₂. Each threshold value isincluded between 45° and 135°, and in particular is equal to 90°.

We are now going to describe the operation of the control unit 702, whenthe device comprises the foldable part 104 ₂ shown in FIG. 5.

In order to control the foldable part 104 ₂, the control unit 702 canimplement the two control variants described above for the control part104 ₁, with the difference that the single guard plane 502 is activatedwhen at least one of the detection layers 408 and 410 is activated.

We are now going to describe the operation of the control unit 702, whenthe device comprises the foldable part 104 ₃ shown in FIG. 6.

The control unit 702 commands the two detection layers 408 and 410,either in “capacitive detection” function, or in “electrostatic guard”function. In that way, each of the two surfaces 404 and 406 of thefoldable part 104 ₃ is alternately a detection surface and a guardsurface, depending on the position of the foldable part 104 ₃, such asshown in FIG. 8.

In that way, when one of the detection layers is used in detection, theother detection layer is used as guard plane, and vice versa. Forexample, when the movable part 104 ₃ is folded back: the inner layer 408is commanded to perform the guard function by being placed at guardpotential by the control unit 702 and the outer layer 410 is commandedto perform the detection function, and when the movable part 104 ₃ isopen and reaches an angle greater than a set angle relative to thesurface of the apparatus 102: The inner layer 408 is commanded toperform the detection function and the outer layer 410 is commanded toperform the guard function by being placed by the control unit 702 atthe guard potential.

In other words, and more generally, the inner layer 408 and the outerlayer 410 are set up such that the function done by each layer is chosendepending on the angle β between the foldable part 104 ₃ and the userapparatus 102, such that:

-   -   when β is less than a first set value β₁, the inner layer 408        performs a guard function and the outer layer 410 performs a        detection function, and    -   when β is greater than a second set value β₂, the inner layer        408 performs a detection function and the outer layer 410        performs a guard function.

Of course, the first and second threshold values can be identical ordifferent. The threshold value or values can be included between 45° and135°, and in particular equal to 90°.

In general, in all the embodiments described, when a detection layer isnot used/activated in detection, for example because it is deactivatedor activated in guard, at least one of the electrodes from this layercan be used sporadically, on request or at a set frequency, in order todetect the presence of objects opposite the surface associated with saiddetection layer and the type of object detected (for example a tablewhen it involves the outer surface, a display screen when it involvesthe inner surface, etc.).

We are now going to describe a user apparatus according to theinvention.

FIGS. 9-11 are schematic representations of an example implementation ofa apparatus according to the invention provided with a device accordingto the invention comprising a fixed part coming to replace a rear shellof the portable apparatus.

The device 100 equipping the apparatus 102 comprises a fixed part 106arranged in order to be substituted for a rear shell normally equippingthe portable user portable apparatus 102.

This fixed part 106 comprises a connection device 902 intended to beenclosed in the portable apparatus 102 and to implement the necessaryelectrical connections for interfacing the detection layers 408 and 410of the foldable part 104 of the accessory 100 with the control andprocessing modules of the portable apparatus 102. The device 100therefore comes in the form of an accessory which is an integral part ofthe portable apparatus 102 to which it contributes additional functionsof capacitive detection.

FIG. 10 shows a representation of the apparatus 102 from FIG. 9, set ona surface 1002, such as a table, where the foldable part 104 is open soas to obtain a touch screen keyboard assembly which allows performing“hovering” type controls for games, for example directly with the user'shand 1004 or finger. These controls can include a joystick control byinclination of the user's hand 1004 above the foldable part 104 in orderto direct an object displayed on the screen 110 and can do so withouthiding the screen with the hand 1004.

FIG. 11 shows a representation of the apparatus 102 from FIG. 9, set onthe surface 1002, such as a table, where the foldable part 104 forms anangle β greater than or equal to 90° with the screen 110 of theapparatus 102.

The screen 110 of the user apparatus 102 is provided with a capacitivedetection layer/pad in order to detect with and/or without contact oneor more command objects, such as a hand with one or more fingers towardsthe surface involved.

The detection of the hand 1004 by both the inner layer and by thedetection layer of the display screen 110 serves to implement adetection volume formed between the foldable part 104 and the displayscreen 110.

Of course, the invention is not limited to the examples which were justdescribed and many improvements could be made to these examples withoutleaving the scope of the invention.

The invention claimed is:
 1. A device for a portable electronic userapparatus comprising: a foldable part in order to cover at least onepart of said user apparatus when it is folded onto said user apparatus,wherein said foldable part comprises at least two layers, one of thelayers configurable to act as a capacitive detection electrode andanother of the layers configurable to act as a guard layer placed at aguard potential for guarding the capacitive detection electrode: a firstof said at least two layers being further configurable to perform acapacitive detection function of at least one command object located onone side of said foldable part; and a second of said at least two layersbeing further configurable to perform a capacitive detection function ofat least one command object located on another side of said foldablepart; in order to trigger a function in said user apparatus.
 2. Thedevice according to claim 1, characterized in that each of said firstand second of said at least two layers is configured for being activatedfor detection in turn, depending upon a relative position of thefoldable part with respect to the user apparatus, whereby for a givenposition of said foldable part just one of said layers performs thedetection function.
 3. The device according to claim 1, characterized inthat: each of said first and second of said at least two layers isconfigured to act as a capacitive detection electrode; and the foldablepart further comprises at least one guard plane arranged between thefirst and second of said at least two layers of the foldable part andconfigured for being placed at the guard potential in order to guard atleast one of said first and second of said at least two layers duringthe detection of at least one command object.
 4. The device according toclaim 3, characterized in that it comprises a single guard planearranged between the first and second of said at least two layers of thefoldable part in order to guard each of said layers.
 5. The deviceaccording to claim 1, characterized in that each of said first andsecond of said at least two layers is configured for performing in turnthe role of: either the detection function; or a guard function for theother of said capacitive detection layers by being placed at analternating guard potential (V_(G)); where the function performed byeach of said layers depends on a relative position of said foldable partrelative to said user apparatus.
 6. The device according to claim 1,characterized in that it additionally comprises at least one means ofcontrol to determine, depending on a position of the foldable part,which of the layers performs the detection function in order to activatethe electrodes from said layer in a measurement mode.
 7. The deviceaccording to claim 6, characterized in that the means of control isfurther arranged in order to control placing the electrodes from theother electrode layer in the foldable part at the guard potential(V_(G)) in order to perform the guard function.
 8. The device accordingto claim 6, characterized in that the control means comprises a means ofmeasurement of the position of the foldable part.
 9. The deviceaccording to claim 1, characterized in that at least one layer isfurther configurable to perform a detection of at least one commandobject with or without contact.
 10. The device according to claim 1,characterized in that it is removable and includes at least one means ofconnection to the user apparatus.
 11. The device according to claim 10,characterized in that the means of connection is incorporated in aportion of a shell connected to the foldable part and arranged in orderto be substituted for or arranged on a rear shell of the user apparatus.12. The device according to claim 1, characterized in that it is anintegral part of the user apparatus.
 13. The device according to claim1, characterized in that the foldable part comprises at least onetransparent area and at least one of the layers comprises, at saidtransparent area, electrodes made of a transparent material.
 14. Thedevice according to claim 1, characterized in that the foldable partcomprises at least one opaque area and at least one of the layerscomprises, at said opaque area, electrodes made by PCB technology. 15.The device according to claim 1, implemented for the user apparatusprovided with a screen, characterized in that the foldable part isconfigured in order to be positioned on or against said screen when itis folded.
 16. A portable computer user apparatus comprising the deviceaccording to claim
 1. 17. A method of providing object detection for aportable electronic user apparatus, comprising: covering at least a partof said user apparatus with a foldable part, wherein said foldable partcomprises at least two layers, one of the layers configurable to act asa capacitive detection electrode and another of the layers configurableto act as a guard layer placed at a guard potential for guarding thecapacitive detection electrode; detecting objects using a first of saidat least two layers on a first side of the foldable part while guardingthe first layer with a guard potential; detecting objects using a secondof said at least two layers a second side of the foldable part whileguarding the second layer with the guard potential; and triggering afunction in said user apparatus based on the detection of the objects.18. The method according to claim 17, further comprising activating eachof said first and second of said at least two layers for detection inturn, depending upon a relative position of the foldable part withrespect to the user apparatus, whereby for a given position of saidfoldable part just one of said layers performs the detection function.19. The method according to claim 17, further comprising: configuringeach of said first and second of said at least two layers to act as acapacitive detection electrode; and maintaining a plane at the guardpotential between the first and second of said at least two layers ofthe foldable part in order to guard at least one of said first andsecond of said at least two layers during the detection of at least onecommand object.
 20. The method according to claim 19, further comprisingforming a single guard plane arranged between the first and second ofsaid at least two layers of the foldable part in order to guard each ofsaid layers.